Convertible type aircraft



Aug. 31, 1948. J. c. QUADY E AL 2,448,392

CONVERTIBLE TYPE AIRCRAFT Filed April 4, 1946 9 Sheets-Sheet 1 FIGI J. C. QUADY ET AL CONVERTIBLE TYPE AIRCRAFT 9 Sheets-Sheet 2 Filed April 4, 194a Au .31,194s. J. c. QUADY ETAL 2,448,392

CONVERTIBLE TYPE AIRCRAFT 'Filed April 4, 1946 9 Sheets-Sheet 5 Aug. 31, 1948. J. c. QUADY ET AL I CONVERTIBLE TYPE AIRCRAFT Filed April 4, 1946 9 Sheets-Sheet 4 Aug. 31, 1948. J. c. QUADY ET AL CONVERTIBLE TYPE AIRCRAFT 9 Sheets-Sheet 5 Filed A rii 4. 1946 C L M KAN \\N I 1 mun 3 @F t g. N h fi 3 a m J. c. QUADY ET: AL

CONVERTIBLE TYPE AIRCRAFT Aug. 31, 1948.

9 Sheets-Sheet 6 Filqd @pril 4, 1946 J. c. QUADY ETAL CONVERTIBLE TYPE AIRCRAFT Aug. 31, 1948.

Filed April 4. 1946 '9 Sheets-Sheet 7 Aug. 31, 1948. J. C. QUADY El'AL CONVERTIBLE TYPE AIRCRAFT 9 Sheets-Shee 8 mww mww

Aug. 31, 1948. J. c. QUADY ET AL CONVERTIBLE TYPE AIRCRAFT 9 Sheets-Sheet 9 Filed April 4; 1946 Patented Aug. 31, 1948 CONVERTIBLE TYPE AIRCRAFT John C. Quady, Pasadena Hills, and William L.

Davis, Jr., Normandy, Mo.

Application April 4, 1946, Serial No. 659,620

12 Claims.

This invention relates to an aircraft, and with regard to certain more specific features, to an aircraft combining the desirable characteristics both of a helicopter and an airplane.

Among the several objects of the invention may be noted the provision of an aircraft which combines in its functions the close maneuverability and low landing and take-off speeds of a helicopter and the high-speed performance of an airplane; the provision of an aircraft of the class described having an operator-control systern which is simple .to operate, being operated essentially the same for a given maneuver under conditions either of helicopter or airplane operation or a combination of both; and the provision of an airplane of the class described which is practicable to build, reliable in structure and safe in operation. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. 1 is a general top plan;

Fig. 2 is a side elevation of Fig. 1;

Fig. 3 is a front elevation of Fig. 1;

Figs. 4-8 are diagrammatic side elevations illustrating different maneuvers, landing gear .being omitted;

Fig. 9 is a diagrammatic plan view showing operating controls;

Fig. 10 is a diagrammatic side elevation of said controls of Fig. 9;

Fig. 11 is an enlarged horizontal section taken on line IIH of Fig. 10, showing the details of a pylon control mechanism;

Fig. 12 is a vertical section taken on line l2! 2 of Figs. 10 and 11;

Fig. 13 is a vertical section taken on line 13-43 of Fig. 11; V Fig. 14 is a horizontal section taken on line I l-44' of Figs. 12 and 13;

Fig. 15 is a diagrammatic perspective viewof certain control elements, being extended in Fig. 19;

Fig. 16 is an enlarged detail section taken on line l6l6 of Fig. 15;

Fig. l'lis a horizontal detail section taken on line |1 |1 of Fig. 8;

Fig. 18 is a horizontal detail section taken on line |8l8 of Fig. 10;

Fig. 19 is a perspective view of certain control elements, being extended in Fig. 15; and,

Fig. 2G is a vertical section taken on line 20-20 of Fig. 15.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

As between Figs. 15 and 19, the Roman numerals indicate how these figures may be read connectedly.

As is known, present-day helicopters have advantages of extreme maneuverability and low landing and take-off speeds, making them very useful in cramped quarters. But helicopters are essentially low-speed aircraft. On the other hand, the conventional airplane is a relative-1y high-speed aircraft but suffers the disadvantage of requiring high landing and take-off speeds. Also, it is not as maneuverable as the helicopter. The present invention provides a simple, safe, easily controlled aircraft combining the advantages of both the helicopter and the airplane.

Referring now more particularly to the drawings, Figs. 1-3 show the general appearance of the new aircraft. It comprises an air frame 5|, carrying wings 53 and 55, fixed stabilizers 51 and 59, and a fin 6 I. Control surfaces include ailerons 63 and 65 on the wings 53 and 55, respectively; elevators 61 and 69 attached to the stabilizers 51 and 59, respectively; and a rudder surface H attached to the fin 6|.

Pivoted to the air frame 5| at 12 are a pair of pylons is rigidly connected at 15. These pylons may be moved from a horizontal position such as shown in Figs. 1-3, through essentially a angle to a vertical position such as shown in Figs. 4 and 6, for example. They may also assume intermediate positions. Each pylon 13 carries an air screw 11. The air screws 11 are phased to prevent interference. Both screws are driven from a vertically disposed internal combustion engine 19 (Figs. 9 and 10) through a drive (to be described) which is effective, regardless of the angular positions of the pylons 13. Thus power may be delivered uninterruptedly from the engine 19 to the phased screws 11, regardless of the angular positions of the pylons 13. The screws may be referred to as propellers when the .pylons are down in the Fig. 2 position (-for example) and as rotors in the Fig. 4 position ,(for example). They are designed for both functions.

The pylons 13 respectively carry independently 3 moving control surfaces BI and 83 pivoted at B5 and 81, respectively. Each surface BI and 83 is in two parts, one on each side of its respective pylon, but both parts are effective as one surface. As will be shown, the surfaces 8! and 83 may be moved together or differentially.

Complete control of the aircraft in all aspects of its operation, including both helicopter and airplane operation, is supplied from a control wheel W (Figs. 9, and and a fore-and-aft swinging control stick S. The stick S swings forward and backward on a horizontal pivot 89 (Fig. 15). The wheel turns with respect to the stick S in a bearing 52. Either under helicopter or airplane aspect of operation, steering is accomplished to the right by rotating wheel W to the right, and to the left by rotating'the wheel to the left. Pitching is accomplished by moving the wheel W backward or forward, pivoting of the stick S occurring then at 89. Both of these controlling operations (steering and pitching) may the controls, the main drive will be described.

Both pylons are pivoted, as stated, at 12, about an axis which is essentially over the center of gravity of the craft. Each pylon is hollow and carries a longitudinal drive shaft, as indicated at 9|. At the outer ends of the drive shaft 9| are said rotor propellers 11, respectively. At the inher ends of the shaft 9|, near the pivot 12, are equal bevel gear drives 93 from a countershaft 95. A bevel gear drive 91 connects with a second countershaft 99 and a third bevel gear drive 'IDI connects the countershaft 99 with the engine 19. Suitable declutching means is associated with the engine 13, indicated generally at I93 but not detailed since such is conventional. It will also be understood that the gudgeons 10 forming the pivots 12 of the pylons 13 are carried upon suitable bearings in the frame of the ship and that their center lines are coaxial with the ship as an airplane but to lift it as a helicopter.

The may therefore be referred to as rotors or propellers, depending upon whether they are functioning in helicopter or airplane aspect. They may be of the variable pitch variety adapted to be adjusted either together or differentially, but since propeller and rotor pitch adjustment means of this nature are known, these will not be detailed. It suflices to state that by rotor pitch control, including differential pitch control for controlling in roll while hovering, it is possible to control the craft for hovering in a side wind or under an eccentric loading condition with respect to the plane of symmetry, or for causing sideward motion of the craft. This is accomplished by a change in the relative thrust between the rotors as a result of'changing their relative pitch, thus providing a rolling moment to accomplish the desired motion. The relative pitch of the rotors may be changed by a separate rotor pitch control, not shown herein, but which may be of the type shown in U. S. Patent 2,330,842. By propeller pitch control (operating'as an airas shown at plane) the usual advantages may be attained in this respect. It is to be understood, however, that the controls hereinafter to be described are independent of any such variable rotor pitch adjustments.

The pylons are constrained to move together and can be moved from the horizontal (Fig. 2) to an essentially vertical position (Fig. 4) or any intermediate position (Fig. 7) by the control means shown in Figs. 9-14. This control means consists in a pair of vertical guides I carrying vertically movable sliders I01. Connecting rods I99 are pivoted at III to the sliders and at II3 to the respective pylons 13. The guides I05 are suitably fastened to the frame of the ship.

Also attached to the frame of the ship are two brackets II5 which rigidly anchor opposite ends of a stationary hollow piston rod II1 on which is a stationary piston I29. Carried around the piston rod H1 and piston I29 is a hollow cylinder H9. This cylinder has brackets I2I which slide between angles I23 and upon a plate i25 (Fig. 12) attached to the frame 5|. The hollow piston rod H1 is connected with the inside of the cylinder IE9 on opposite sides of the piston I29 by means of ports I21. Hydraulic fluid can be fed to either set of ports I21 through one of the pair of inlets I3I associated with the hollow piston rod on the outside of the cylinder H9. The connections I3I are alternatively inlets or outlets.

The connections I3I are under control of suitable conventional valve means such that when fluid under pressure is admitted to one port I3I, the other port I3I is connected to exhaust and vice versa, thus making it possible to move the cylinder II9 back and forth with respect to the fixed hollow piston rod H1 and the guides. The purpose of this movement is simultaneously to control the two sliders I91, one of which is on each side of the ship under a pylon 13. This control is effected on each side by a pair of cables I33 and I35. Description of one side (the lower side) of Fig. 11 will be sufficient to disclose the operation of both sides. Both cables I33 and I35 (on a side) are anchored to the slide I91, I31. Cable I33 passes downward and under a pulley I39, then around a corner pulley MI which is carried on a fixed pivot in the frame. The cable then passes over a second corner pulley I45 also on a pivot fixed in the frame. The cable then passes around a pulley M1, carried upon a pin I49 located on one of said brackets I2 I. It will be recalled that brackets I2I are carried with the cylinder H9. The cable then passes under a pulley I5! which is carried on a pivot pin I53 fixed in the frame. The cable then passes over a second pulley- I55 coaxial with the pulley I41 on the pin I49 and finally to an anchor I51 on the frame.

The cable I35 extends from the upper side of the slider I01 and passes over an upper pulley I59 and then down under a pulley I6I on the frame; thence around two horizontal pulleys I63 and I65 on the frame. The cable I35 then passes over a pulley I61 carried on a pin I69 associated with one of the brackets I2I of the cylinder II9. It then passes around a pulley I1I pivoted in the frame and then over a second pulley I13 also car ried on the pin I69. The cable then passes to an anchor I14 attached to the frame. In the upper portion of Fig. 11, like reference characters indicate like parts to those just described.

Thus when the cylinder is moved back from the position shown in Figs. 10 and 11 to an intermediate position shown in Fig. 14, the pylons are lifted to an intermediate position. When the cylinder reaches the rear end of its stroke, the

pylons are lifted into a vertical position. The

A purpose of the sets of pulleys I41, I5I, |55and I61, I'll and- I13 is to provide a block and tackle arrangementwhich multiplies the motion of the "The supplementary control surfaces 8| and 83, respectively pivoted to the pylons 13, are controllable either together or differentially. Each surface (Figs. 9, 10, and 19) is under control of a crossed cable I15, which provides a flexible connector between a small pulley I11 and a larger sector |8| and an idler pulley I19. These pulleys have bearings in the respective pylons. posite ends of each cable I15 are connected to op- The opposite ends of sectors |8| attached to the pintles I80 of the respective supplementary surfaces 8| and 83. Each pulley I19 and I11 and sector |8| is rotary with respect to its respective pylon.

- Each pulley I11 also forms a rigid cluster with a pulley I83. As will be shown, the pulleys I83 are under control of other cables to be described.

However, whenever the pylons 13 are angled from one position to another, relatively to the pulleys I11 and'l83, there will be a planetary action of sectors I8I, through the cables I15, with respect to the pulleys I11. Sectors |8I are larger in diameter than the pulleys I11; Hence if the attitudes of the supplementary surf-aces 8| and 83 are horizontal when the pylons are horizontal (Fig. then when the pylons are simply raised 90, without other adjustments, the attitudes of the surfaces 8| and 83 will beat about 30 with respect to the axes of the pylons 13. In other words, the supplementary surfaces 8| and 83 will also rotate in the same directions as the pylons but through a smaller angle, by virtue of the stated difference in pulley diameters. leys I11 and sectors |8| were the same size, the supplementary surfaces would remainhorizo'ntal as the pylons move. The diameters of sectors |8| are such that the neutralpositions of the supplementary surfaces BI and 83, when the pylons are-Vertical, makes the stated angle of about 30 which is shown in dotted-line position at the top of Fig. 10.

The remaining control surfaces (i. e. ailerons 83, 65; elevators :61, 69; and rudders 1|) perform the following functions when the machine operates as an airplane: The ailerons roll the craft for banking in a turn, the elevators cause a itching moment to raise or depress the nose, and the rudder causes a yawing moment to turn the craft. The supplementary surfaces 8| and 83 perform additional functions. First, they enable the craft to be maneuvered as a helicopter and to provide stability and control over the craft while in transition from helicopter flight to airplane flight. While the craft is operating as an airplane they provide some trim, that is, they provide some lift to'bala-nce the pylon forward overload.

Referring to said Figs. 9, 10, and 19, rudder action is obtained by angling a rudder bar I85 attached to the rudder 1|. To opposite ends of the rudder bar I85 are attached opposite ends of a cable I81 which passes forward over the following pulleys I89, I9l, I93, I95, I91, |99, I, 203, 205, 201, hand back to the opposite side of the If the pulailerons B3 and 65.

6 rudder bar I85. The pulley I99 is fastened on the lower end of a control shaft 2| I, which carries a pulley 2|3. This pulley H3 is under control of a cable 2 I 5 which passes over opposite pulleys 2" on the post S and around a pulley 2I9, connected with the wheel W. Thus by turning the wheel W right or left, the rudder 1| is turned to yaw the ship for a right or left turn, respectively. This will be effective in any fore-and-aft position of the wheel W. The upper end of the control shaft 2| I'c'arries a grooved slide bar 22I,

in the groove of which is operative the lower ball end 222 of acontrol lever 223. Turning of the wheel W also turns bar 22l, for purposes which will appear.

As is known, an airplane can seldom be placed in a well coordinated turn simply by yawing. It must ordinarily also-be banked for a turn and this is accomplished by connecting oppositely moving portions of cable I81 to opposite horns 225, connected respectively to the opposite When one side of the cable I81 moves forward, the other side moves back and the coordination is such that for a right turn,

the left-hand aileron is depressed and the righthand one is lifted for obtaining the proper bank. Conditionsare the reverse for a left turn.

The elevators 61 and 69 operate together under control of an elevator bar 221, to opposite ends of which are connected cables 229. These cables pass forward over the following pulleys: pair 23 I, pair 233; pair 235, pair 231, single 239 and pair 2. Pulleys 23I, 231 and 239 are shown in Figs. 9 and 10 but not in Figs. 15 or 19. The other ends of the cables are connected to the post S at 243 and 245, the former connection being above the pivot 89 and the latter below. Hence when the post S is rocked forward or backward by pushing and pulling wheel'W, the elevators are controlled. A forward push on the post from the steering wheel W will depress the elevators so as to depress the nose of the ship and vice versa.

From the above it will be seen that by rocking the post S and turning the wheel W, all of the conventional controls are obtained for the ailerons,.elevators and rudder, for use when the pylons 13 are horizontal and the ship being flown as an airplane.

The steering wheel W is also capable of effecting control of the supplementary surfaces 8! and 83 so that they will aid in steering the aircraft, both when used as an airplane and as a helicopter. Thus, turning of the wheel W, through action of cable 2|5 on pulley 2 I3, causes rotation of shaft 2H and of grooved bar 22I. This action moves the ball end 222 of lever 223, provided the ball is not coaxial with the shaft 2| I. Lever 223 is carried on a horizontal control shaft 239, to which a pulley 25l is splined for relative axial movement only. Over the pulley 25| is wrapped a cable 253, which passes over the following: Pulleys 255 which are on fixed pivots in the air frame; pulleys 251 which are on movable pivots carried on opposite sides of a sliding bar 259; fixed pulleys 26I, 253, 265, said pulleys I83 which are rotary in the pylons 13; then over fixed pulleys 261, 209; then pulleys 21| (on the same axes as 251 respectively) and over pulleys 213 to complete a circuit.

Pulleys I83 have already been mentioned as those which control the rotations of pulleys I11. Since the latter have the crossed cable connections with the pulleys I19 and the sectors 8|, said cable 253 controls the differential angular positions of the supplementary surfaces 8| and movement between shaft 209 and lever 29L cess 295 in the movable member 259. when the control stick S is rocked backward,

will cause rotation of the gear 299.

2.183. The ildifferential angles through which the --su-pplementary surfaces are turned are opposite with respect "to amedian position. This is true'because ascable pays out'on one side of the pulley. 25| it is drawn in on the other side. This causes the opposite pulleys 183 tobe .oppositely :rotated for any given rotation of the wheel'W.

It should'be remarked at this .point that the degree and sense of differential (opposite) :movement between the supplementary surfaces 8| and 83 is a function of the distance of the ball x222 in onedirection or another from the center of rotation ofthe shaft12| I. is varied will be described later.

How and why this When the supplementary surfaces-8| and 83 are differentially moved by'turning the wheel W,

thermember 259 which supportspulleys 251 and ;2'|| is not moved thereby, since as much of cable \253 pays around pulleys .251 as around the adjacent pulleys 2'.

Equal (non-differential) movements ofthe supplementary surfaces 8| and 83 are'accomplished by moving the-post S forward or backward. For this purpose there'is arranged atthe lower end of the post a pivot connection 215 with a rod 211 reaching to a lever 219;

This lever rotates a rod 28| which carries a slotted bar 283. The ball end 295 of a lever 281 is carried in this slotted bar 283. The lever 281 extends from a control shaft 289. The latter is splined at 299 to a lever 29I. The spline 299 allows only relative axial A ball end 293 of lever 29 cooperates with a re- -Hence the movable'member 259 is moved forward. This equally moves forwardthe pairs of pulleys 291 and 2H. Pulleys 251 draw in equal amounts of opposite portions .of the cable 253 and pulleys 2' pay out equal amounts. This rotates both pulleys I83 clockwise equally (Fig. '19) which, through cables I75, causesthe surfaces 8| and -83 to have theirleading edges raised equally.

When the stick S is rocked forward the action is reversed.

On the upper surface of the member 259. is .a

toothed rack 291, which meshes with' a gear 299 '22| and the degree of differential action established for the supplementary surfaces BI and 83 by turning the wheel W is a function of this adjustment. When the ball 222 is about on the center of the shaft 2| I, the supplementary surfaces are in approximately a 30 position with respect tothe pylon axes when the pylons are vertical.

Provision must also be made for correcting the attitudes of the supplementary surfaces during the transition period in bringing the pylons from vertical to horizontal or vice versa. This is accomplished by means of a cable 30'! which is threaded over a pulley 399 of the lower end of a vertical control shaft 3H and also over pulley 3 l3 and a pulley 3|5 attached to the right- -hand pylon 13. Thus pylon movement causes movement of the cable 301, and rotation of the 'pulley i309 and of the vertical control :shaft r 3| I.

This control shaft has :attached to it a; gear 3|!v which meshes with a circular rack 3|'9 on the control shaft 289 (Fig. 16).

The rack 3|9 and the rack 305'above described are similar in form, being made bycutting circular tooth forms on a shaft to mesh withza gear so that rotation of the rack'will not turn the gear.

The upper end of the control shaft 3|| carries a-gear' 32| which meshes with'an ordinary rack 323 on theside of the bar 303. The bar 393, it will be remembered, controls the positionof the center 30| of the gear 299. Thus whenthe pylons are angled, as during a transitional adiustment of the same,the rack member 303 moves backward or forward. Assuming member 259 to be a body of reference. the gear 299 will then 1 roll on the rack 291' and through its mesh with .222 in the grooved leverr22l.

'cause of the splined connection 250.

rotors 11 the craft'rises in still air.

the circular rack 305 control the axial position of the bar 249 andhence the position of .the'ball Thus, the angular positions assumed by the pylons exert a corrective action upon the amount of adjustment that. can be delivered fromthe wheel W to the supplementary surfaces 8| and 83, depending upon the pylon attitude. When thepylonsraise, the shaft 249 moves backward (to the'right in Fig. 15).

Operation is as follows:

Assuming first helicopter flight, fluid isadmitted to the right-hand end of thecylinder I I9 to move it backward and thus raise the pylons 13 to a vertical position such as shown in Figs. 4,5 and 6. Operation of the rotors Tl fromthe engine 19 will now cause them to operate as vertical air screws to lift the craft vertically.

Two things occur in connection with them:- ward movement of'the pylons. First, this movement changes the ratio of the motion of the supplementary surfaces 8| and 83 to that of the control wheel W. Second, for a given rotation of the control wheel W',.this affects the sense in-which the supplementary surfaces deflect'differentially from their mean positions. The reason for this will appear.

As'thepylons rise, the gears 32| and 3l'l-rotate in the direction shown by the arrows inFig.,l5. This is due to the action of the cable 30'|-as it'is driven by the pulley 3|5, the latter rotating with ment between shaft 289 and the lever 29l; .Rack .303 also is moved backward in the direction shown by the arrow thereon. Gear 299 then-rolls on the rack 291 in the direction shown bythe arrows. This pushes the circular rack305 backward, as shown by the solid arrow thereon. This does-not affect the position of the pulley 25|, be-

The ball end 222 of arm 223 is at this timepushedeto the center of the channel in the lever 22 |,'that.is. on the center line of the shaft 2| This produces a neutral position of parts for helicopter flight, provided wheel W andstick Sarein neutral positions. The surfaces 8| and 83 arethen as shown in dotted lines in Fig. 10, that is; at about30 to the pylon axis.

Next, assume that due-to the operation of the The wheel W is at this time pulled back for hovering as a helicopter. This tilts back the stick Sand moves the rod" 21'! forward, rotating shaft z8lz'anticlockwise (looking down). The ball end 285 of the lever 28'! moves anti-clockwise. This rotates lever '29l anti-clockwise. This moves the member 259 forward, which carries with it the pairs of pulleys 251 and 21 This action through the cable 253 causes both pulleys I83 to rotate clockwise the same amount, it being understood that the pylons are at this time in a vertical position. This rotates the supplementary surfaces 8| and 83 the sam amount and in the same direction, due to the action of the cables I15.

faces 8| and 83 are moved to essentially a vertical position so that the Slipstream of the rotors ll passing over surfaces 8|, 83 will induce no pitching moment.

time pushed forward from its position for still air thus reversing the directions of all components described above so that the leading edges of surfaces BI, 83 will be moved forward. The result M will be as shown in Fig. 5 wherein the forward tilt of the surfaces 8| and 83 act in the slipstream of the rotors 11 to tilt the craft forward to provide a forward negative pitching moment (nose down) with a force component from the rotor air stream to balance the wind force. This tilt under these Fig. 5 conditions is less than would have occurred if the wheel W were in its neutral position as in Fig. 10. This is because when the wheel Wis in neutral position the control surfaces 8| and 83 are at the stated 30 angle to the pylons. In Fig. 5 they are adjusted to less than 30. At any time that it is desired to permit the craft to move forward under the Fig. 5 conditions, the wheel is pushed forward closer to the neutral, so that the angle of the surfacesBl and 83 is greater with respect to the pylon axis, thus giving a greater forward tilt and a greater forward component of thrust overbalancing the wind thrust.

move the craft forward as a helicopter.

AS stated, if at the time of the initial rise of the craft there is no head wind, the wheel W may be pulled back to attain the conditions of Fig. 4, for hovering. This Fig. 4 setting is even effective for hovering in a slight tail wind if the center of gravity with the pylons up be assumed to have moved back some behind the centers 12. For some backward movement of the craft the wheel may be pulled back even more to pull back the leading edges of the surfaces BI and 83 to attain from the slip stream some backward tilting action on the surfaces 8| and 83. This causes a positive pitching moment (i. e.,nose up) which tilts the entire craft backward.

It will be observed that pulling back of the wheel W not only causes the'pairs of pulleys 251 and 2' to move forward but, through action of the rack 291, causes the gear 299 to force backward the rack 385. This had the effect of moving the ball end 222 of said lever 223 more rearering or forward flight is desired. While in this rearward position, the ball end 222 of lever 223 is always rearward of the center line of rotation of shaft 2 and hence always produces differen-J tial angling of surfaces 8| and 83 in the same The result will be as shown in Fig. 4 wherein the sur.-.

Next assume the craft hovering; in a slight head wind. The wheel Wis at this i This Will 1 10 sense for a given direction of rotation of the wheel W.

Assume next that the wheel W is turned to the right while hovering as in Fig. 4 (for example). Pulley 2|3 is rotated anti-clockwise looking down, or as shown by the arrow thereon. The rear end of the channel lever 22| moves in the direction shown by the arrow at that point. This causes the ball end 222 of the arm 223 to move likewise, which rotates pulley 25| anticlockwise, as shown by the arrow thereon. This, through cable 253, rotates the pulleys I83 in opposite directions. The resulting positions of the supplementary surfaces 8| and 83 are then as shown in Fig. 6, the same being oppositely angled from a mean vertical position. If the wheel had been rotated in the Fig. 5 aspect of the surfaces 8|, 83, the latter would have'angled oppositely around their mean position shown which also would have resulted in turning. Thus in helicopter aspect, when the supplementary surfaces 8| and 83 are in oppositely angled positions from any mean position (Fig. 6 for example), the down draft of air from the rotor causes a turngying moment on the craft to turn it to the right.

Obviously, if the wheel W is turned to the left, the

supplementary surfaces 8| and 83 will be inversely positioned, thus causing the craft to be turned to the left. The turning in both cases is 30 021 or near a vertical axis.

Next, assume the craft is to be headed with moti-on into the wind without turning (not hovering). The rotor axes must be tilted forward to supply an unbalanced forward component of thrust. This is not accomplished by lowering the pylons, but the supplementary surfaces 8| and 83 arerotated together with respect to the pylons to an angle greater with respect to the pylons than shown in Fig. 5, so that the rotor blast striking them causes a substantial negative pitching moment (i. e. to depress the nose) which tilts the whole craft into the wind. This isdone by pushing further forward the wheel W. Thus increased forward speed is obtained by pushing the wheel W further forward, which tends to turn .both supplementary surfaces 8| and B3 anti-clockwise (referring to Fig. 5) so as to increase the forward negative pitch.

If it be assumed that the craft is hovering or fi h-loperating in a side wind, it will be understood that control may be accomplished by a combination of the turn on the wheel W (right or left) and a forward or rearward push or pull thereon. This produces a. combination of the above effects. Thus 55,;iwhen the wheel W is pushed forward, the mean.

positions of the supplementary surfaces 8! and are moved so as to bring their upper edges more forward; and any turning of the wheel will produce opposite differential angling of the surfaces 69, .8! and 83 about the new mean position. Thus the pilot can advance forward while turning in either direction, while operating as a helicopter (pylons up, or nearly up).

Summing up the helicopter flight conditions, at forward deflection of the leading edges of the supplementary surfaces 8| and 83 favors forward motion of the craft by tilting the craft forward. which depresses the nose. R'earward deflection of the supplementary surfaces favors rearward mo- 7 tion of thecraft. Forward deflection of the left supplementary surface and rearward deflection of the right supplementary surface favors a turn to the right. Opposite deflections favor a turn to the left.

By differentially changing the pitches of the 11 rotors Tl (in the manner for each of which this is usually accomplished and requiring no description here) the craft may be tilted to the right or left, thus adding this component of 'control for causinga sidewise motion by sidewise drag of the rotor due to the tilt.

Although the conventional aileron, stabilizer and rudder surfaces have, during the above helicopter operations, been also subject to control, their operations are not detailed here since they have no effect on the craft while hovering or moving relatively slowly as a helicopter.

Next, the matter of transitional flight will be considered. This occurs when the pylons are let down'as illustrated in Fig. '7. Vlfhen the pylons are still nearly vertical the craft is capable of forward motion as a helicopter up to a velocity great enough to cause the wings to supply a lift equal to .the weight of the craft.

In partial or full airplane attitude the supplementary surfaces 8i and 83 must, in assisting the ailerons have their relative motions reversed from the helicopter sense, and in moving together to assist the elevators, move through smaller angles. Thus, as shown in Fig. 8,'the amount of possible differential movement of the supplementary surfaces BI and 83 about a mean position shown in dotted lines is reversed from that shown in Fig. 6. That is to say, the same sense of turning effect on the craft is produced by opposite deflection of the supplementary surfaces in the Fig. 8 transitional attitude This is caused by pulley 315 turning anti-clockwise (Fig. 19) as the pylons are depressed. This moves the cable Sill in a direction such that the pulley 369 is turned anti-clockwise (looking down), which turns the gear 32! anti-clockwise and moves forward the member 303, which rolls the gear 299 on the rack 291, thus causing the ball end of the lever 223 to be positioned forward in the grooved lever ZZI, i. e., ahead of shaft 2| l. This reverses the differential movement between the supplementary surfaces, as caused by any movement of the cable 253, obtained by turning the wheel W. Also, the anticlockwise motion of the gear 3!! (looking down) also moves the rack bar shaft 289 so as to cause the ball end of the lever 28'! to be closer to the center of the shaft 28L This causes less motion to be transmitted from the lever 29! to the inemher 259 when the stick S is moved forward and backward, to control the surfaces BI and 83 simultaneously to assist the elevators 61 and 69. Thus the differential movements of the supplementary surfaces 8i and 83 (responsive to turning of wheel W) are automatically reversed in sense and equal movements (responsive to fore and aft movement of stick S) are made smaller in magnitude as the pylons descend toward and into the airplane attitude of Fig. 2.

When the craft is in airplane attitude (Figs. 1-3) it may be steered to the right by rotating the wheel W to the right. This rotates pulley 2l3 anti-clockwise, looking down. This through cable l8! controls the rudder in the proper direction for the desired right turn. At the same time, the forward end of the channel lever 22! moves anticlockwise, looking down. Thus the ball end 222 of the lever 223 moves likewise, rotating the shaft 249 clockwise, looking forward. Thus the pulley 25! rotates clockwise and the cable 253 causes opposite rotations of the opposite pulleys I83. These in turn, through the cables H5, cause opposite movements of the supplementary surfaces BI and 83 in the proper direction for the desired right bank which is required for the right turn. At the same time, the opposite levers'225; which control: the opposite ailerons 63 and 55, are moved oppositely by the oppositely moving reachesof the.

It may be noted from Figs. ,9. and 10 that these levers 225 are'coupled into the rudder cable Hll.

rudder cable for the purpose. In Fig. 9 the levers are shown as being connected to opposite members 226, which effect theailer-on control inthe usual way.

Thus the supplementary surfaces 8| and 83' in an airplane attitude act like the ailerons 63% and 65, that is, they are differentially movable in response to turning of wheel W in coordination-x Pitching moments are obtained in the usual way by moving the stick S back and forth, and the resulting effect is both with the ailerons.

upon the elevators 6'! and 69, and the surfaces 8i and 83 which all move together. However,

surfaces 8| and 83, in coordinating with the elevators in airplane attitude, have less sensitivity than these surfaces have when operating togetherin helicopter attitude.

For pitching movements, the stick'is pushed forward or backward as usual, which involves the' described control of the elevators 61 and 6}]. Under such conditions the wheel W is not turned and consequently the rudder 'H is not turned, nor are the ailerons 63'and 65 given any movements. The movements of the surfaces 8| and'83 are, as indicated, only slight. Thus the function of the supplementary surfaces in airplane attitude in straight flight is slightly to assist the conventional control surfaces which provides greater controllability of the craft. only as parallel operating supplements. when the wheel is pushed forward the supplementary surfaces assist the elevators in lowering the nose; and when the wheel is pulled backward these surfaces assist in raising the nose. The sensitivity of the supplementary surfaces when.

However, they act acting as elevator aids is a function of the pylon orientation, the sensitivity decreasing as the pylons go down to horizontal position. being a minimum in the airplane attitude of Fig. 2.

The apparatus may be built in relatively comresult in forward movement of 'ball.222'in the slot- Thus, when the pylons are down this ball 22!. 222 is well forward of the axis of shaft 2. When the pylons are up. and stick S in neutral. this ball is at the axis of shaft 2H; but-if the stick S be tilted back by pulling back the wheel W, the ball 222 will be behind the axis of shaft 2| 5. For a given rotation of the wheel W, when the pylons are up and the stick back, ,the supplementary surfaces BI and 83 rotate differentially in one sense (see Fig. 6 for a right-hand turn as a helicopter) and when the pylons are down,-the

same rotation of the wheel W (for a right-handturn as an airplane) will cause said supplementary surfaces 8| and 83 to rotate differentially in the opposite sense so as to coordinate with the differential movements of the ailerons 63 and 65.

This reversal of sense occurs when the ball 222 passes across the center line of the shaft Ml.

Crossing occurs when the pylons have progressed through a small angle down from their vertical Thus 13 positions and the stick has been moved forward almost to neutral. For example, in Fig. 6, which shows a helicopter attitude, a right-hand turn of the wheel has caused the near surface 8| to move anti-clockwise; whereas in the Fig. 8 transitional attitude, a right-hand turn of the wheel has caused the near surface 8| to rotate clockwise. For further pylon adjustments down to airplane attitude the sense of movements of surfaces 8| and 83 is as in Fig. 8.

It will be observed, in addition, that the foreand-aft movements of the stick S also adjust the ball 222 in the groove 22L Since, however, forward motion of the stick S always causes the ball 222 to move forward in the groove 22l, and backward movement of the stick S causes the ball 222 to move backward, the change in sensitivity of control is in one direction or another, depending upon which side of the axis of shaft 2H the ball 222 is on. Thus when the pylons are down, forward motion of the stick S (when ball 222 is already in the forepart of groove 22!) will increase the sensitivity of response of the surfaces BI and 83 to turning of the wheel W. On the other hand, when the pylons are up (ball 222 in the rear end of groove 22!), any forward motion of the stick S will drive ball 222 closer to the center of shaft 2H, and thus decrease the sensitivity of the differential motions of the surfaces 8| and 83 in response to turning of the wheel W.

At some transitional point of the pylons the ball 222 is on the center line of shaft 2 and turning of the wheel has no eifect on the differential movements of the surfaces 8| and 83; but it should be noted that under such a condition the craft has a substantial forward velocity which makes the controlled rudder H and ailerons 63 and 65 effective for a banked turn in response to turning of the wheel W.

It should also be noted that when the slot in lever 283 is parallel to the circular rack 289, any action of the pylons through cable 301 and shaft 3H moves the ball 285 back and forth in 283 without relative rotation of the lever 281. On the other hand, in other adjustments of stick S the groove in 283 may not be parallel to the center line of 289, and under such conditions pylon movement will introduce an incidental angling of the lever 281 but any effect introduced thereby is naturally corrected by the pilot by proper manipulation of the stick S and wheel W to obtain the desired movements of the craft.

Advantages of the invention are that in one aircraft are attained the advantages of helicopter and airplane operation, without their respective disadvantages. The craft, exclusive of engine and ordinary trimming controls, requires only two basic control motions for full control. These are the same whether the craft is operating as a helicopter or as an airplane. These control motions are simply the rotation of the wheel W and the fore-and-aft motion of the stick S. Thus regardless of the mode of flight in which the craft is operating, the operator always performs his control actions in the same sense when a given maneuver is called for. Thus, for example, when it is desired to turn to the right and at the same time raise the nose, the wheel is rotated to the right and pulled back, either when the craft is operating as a helicopter, an airplane, or in transitional flight. Furthermore, the various control surfaces are arranged and interconnected 14 Y for complete control and excellent stability throughout all conditions of flight.

In view of the above, it will be seen that the several objects of the invention are achievedand other advantageous results attained. I

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. An aircraft for airplane and helic'opterattitudes of flight comprising a frame, wings having oppositely movable ailerons for bank and turn movements, stabilizers having equally-movable elevators for pitching movements, pylon means pivoted to the frame and movable from an airplane attitude to a helicopter attitude, air screw means on the pylon means, power means in the frame adapted to drive said air screw means irrespective of the position of the pylon means, sup-- I plementary surfaces on the pylon means and located in the air wash from said air screw means,

a control for the supplementary surfaces, ailerons and elevators having both fore-and-aft and lat- I eral control movements, the supplementary surfaces responding to lateral movements of the control when the pylon means is in an airplane attitude to coordinate with the oppositely movable ailerons for banking and responding to fore- I and-aft movements of the control to function together to supplement action of the elevators, and

means responsive to lifting movement of the pylon means whereby when the pylon means is in elevators, a rudder on the frame coordinated with the ailerons for bank and turn movements, pylon means pivoted to the frame and movable from an airplane attitude to a helicopter attitude, air screw ineans on the pylon means, an engine in the frame, a drive between the engine and the air screw means for driving the air screw means irrespective of the position of the pylon means, supplementary surfaces on the pylon means and located in the air wash of said'air screw means, a coordinating control for the supplementary surfaces, ailerons, elevators and rudder having fore-and-aft and lateral control movements, the supplementary surfaces opposite- 1y responding to lateral movements of the control when the pylon means is in an airplane attitude to coordinate with the oppositely movable ailerons for banking and responding to fore-andaft movements of the control to function together to supplement action of the elevators, and means responsive to lifting movement of the pylon means whereby when the pylon means is in a helicopter attitude in response to the same lateral movement of the control means the angular aspects of the supplementary surfaces are reversed with respect to the air wash and whereby in response to the same fore-and-aft movements of the control the supplementary surfaces function'together but with" a greater sensitivi-tyof 1'6.- sponse.

3. In an aircraft for airplane andlhelicopter attitudes of flight comprising a frame, wings on the frame having oppositely movable ailerons, stabilizers on the frame having equally movable elevators, a rudder on the frame coordinated with the ailerons for bank and turn movements, a pair of pylons pivoted to the frame and movable together from a substantially horizontal airplane attitude to a substantially vertical helicopter attitude, air screws on the respective pylons, an engine in the frame, a branched drive from the engine to the respective air screws and adapted to drive said screws irrespective of the position of the pylons and to phase the motions of the screws, supplementary surfaces respectively on the pylon means and located in the air wash of said air screw means, a coordinating control for the supplementary surfaces, ailerons, elevators andrudder having fore-and-aft and lateral control movements, the supplementary surfaces oppositely responding to lateral movements of the control when the pylon means is substantially horizontal to coordinate with the oppositely movable ailerons for banking and responding to foreand-aft movements of the control to function togetherto supplement action of the elevators, and means responsive to lifting movements of the pylons whereby when the pylons are substantially Vertical in response to the same lateral movement of the control the aspects of the supplementary surfaces are reversed with respect to the air wash and whereby in response to the same fore-and-aft movements of the control the supplementary surfaces function together but with a greater sensitivity of response.

4. An aircraft comprising a frame, a pivoted pylon on the frame movable from a substantially horizontal position for airplane attitude to a substantially vertical position for helicopter attitude, an air screw on the pylon, an engine in the frame for driving the air screw irrespective of the pylon position, wings on the frame having ailerons, stabilizers on the frame having elevators, and a rudder on the frame, supplementary control surfaces on the pylon, control means in the frame coupled with said ailerons, elevators, rudder and supplementary surfaces and arranged to move said supplementary control surfaces together and coordinately with the elevators so that pitching of the aircraft is brought about by longitudinal control movements when the pylon is up or down and to move said supplementary surfaces differentially relative to one another when the pylon is up or down but coordinately with the ailerons whenthe pylon is down, so that turning movements are brought about by lateral movements of the control means when the pylon is up or down. l

5. An aircraft comprising a frame, a pivoted pylon on the frame movable from a substantially horizontal position for airplane attitude to a substantially vertical position for helicopter attitude, an air screw on the pylon, an engine in the frame for driving the air screw irrespective of the pylon position, wings on the frame having ailerons, stabilizers on the frame having elevators, and a rudder on the frame, supplementary control surfaces on the pylon, control means in the frame coup-led with said ailerons, elevators, rudder and supplementary surfaces and arranged to move said supplementary control surface together and coordinately with the elevators so that pitching of the aircraft is brought about by longitudinal control movements when the pylon is up or down and to move saidsupplementary surfaces differentially relative to one another when the pylon is up or down but coordinately with the ailerons when the pylon is down, so that turning movements are brought about by lateral movements of the control means when the pylon is up or down, the same lateral movements of the control mean in the two attitudes resulting in opposite differential movements of said supplementary control surfaces.

6. An aircraft comprising a frame, a pivoted pylon on the frame movable from a substantially horizontal position for airplane attitude to a substantially vertical position for helicopter attitude, an air screw on the pylon, an engine in the frame for driving the air screw irrespectiveof the pylon position, wings on the frame having ailerons, stabilizers on the frame having elevators, and arudder on the frame, supplementary control surfaces on the pylon, control means in the frame coupled with said ailerons, elevators, rudder and supplementary surfaces and arranged to move said supplementary control surfaces together and coordinately with the elevators so that pitching of.

the aircraft is brought about by longitudinal control movements when the pylon is up or down and to move said supplementary surfaces differentially relative to one another when the pylon i up or down. but coordinately with the ailerons when the pylon is down, so that turning movements.

are brought about by lateral movements of the control means when the pylon is up or down, the same lateral movements of the ontrol means in the two attitudes resulting in opposite differential movements of said supplementary control surfaces, and the same longitudinal control movements of the control means in the two attitudes resulting in different sensitivities of said supple-- mentary control movements which coordinate with the elevators.

7. An airplane comprising a longitudinal frame having wings adapting it for forward flight, pylons pivoted at their rear ends to said frame and movable from a substantially horizontal position to a substantially upright position, air screws on said pylons, an engine for operating said air screws regardless of the positions of the pylons, separate supplementary air surfaces on the respective pylons, control means for said surfaces for moving them to angled positions whereby they are effective to roll the ship on a substantially horizontal axis when the pylons are down and to turn the ship on a substantially vertical axis when the pylons are up, and means operative by pylon movement whereby the effect of the control means for said supplementary surfaces becomes angularly reversed as the pylons are moved to their upright positions."

8. An airplane comprising a frame provided with wing surfaces for forward airplane flight, pylon means pivoted to said frame and movable from a substantially horizontal position to a substantially vertical position, air screw means on the end of said pylon means, an engine in the frame for driving said air screw mean-s regardless of the position of the pylon means, supplementary air surfaces on said pylon means, and operating means automatically moving said supplementary air surfaces from a position substantially parallel to the pylon means when down to a position at a substantial angle to the pylon means when the pylon means is up.

9. An airplane comprising a frame provided with wing surfaces for forward airplane flight,

pylon means pivoted to said frame and movable from substantially horizontal position to a substantially vertical position, air screw means on the end of said pylon means, an engine in the frame for driving said air screw means regardless of the position of the pylon means, supplementary air surfaces on said pylon means, operating means automatically moving said supplementary air surfaces from a position substantially parallel to the pylon means when down to a position at a substantial angle to the pylon means when up, control means for relatively angling the supplementary surfaces, and means responsive to positioning of the pylon means causing reversal of the relative angling of the supplementary surfaces responsive to a given movement of said control means.

10. An airplane comprising a frame provided with wing surfaces for forward airplane flight, pylon means pivoted to said frame and movable from a fore-and-aft substantially horizontal position to a substantially vertical position, air screw means on the end of said pylon means, an engine in the frame for driving said air screw means regardless of the position of the pylon means, and supplementary air surfaces on said pylon means, and operating means automatically moving said supplementary air surfaces from a position substantially parallel to the pylon means when down to a position at a substantial angle to the pylon means when the pylon means is up, said last-named angle being other than 90.

11. An airplane comprising a frame, pylon means pivoted to the frame and movable from a substantially horizontal position to a substantially vertical position, a vertically movable slide, a connecting rod linking said slide and the pylon means, substantially horizontally movable power means, a flexible connector including a tackle between said power means and the slide Whereby the movement of the slide is a made fraction of the movement of said power means.

12. An aircraft for airplane and helicopter flight comprising a frame having control surfaces for airplane attitudes of flight, a pylon pivoted to the frame and movable from a longitudinal airplane attitude to an upright helicopter attitude, an air screw at the end of the pylon the thrust of which is changed with change in attitude of the pylon, an engine in the frame adapted to operate said air screw irrespective of pylon position, supplementary control surfaces on the pylon movable bodily therewith as the pylon pivots, a control in the frame adapted to operate said surfaces and said supplementary surfaces on the pylon, said control having longitudinal and lateral control movements and, being so connected with said surfaces that longitudinal and lateral control movements of the control during airplane attitude of flight coordinate all control surfaces for pitching and turning movements respectively of the aircraft, and including means responsive to upright positioning of the pylon whereby substantially said same longitudinal and lateral control movements of the control operate upon said supplementary control surfaces respec tively to effect pitching and turning movements in the helicopter attitude of flight.

JOHN C. QUADY. WILLIAM L. DAVIS, JR.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,353,501 Vogelzang Sept. 21, 1920 1,443,572 Gosline Jan. 30, 1923 1,808,908 Steinmann June 9, 1931 1,903,345 Steinmann Apr. 4, 1933 1,951,817 Blount Mar. 20, 1934 

